Skip to main content

Full text of "Alexander von Humboldt"

See other formats

ALEXANDER  VON  HTJMBOLDT.                175
circumstances, the latent forces which caused inequa-
lities and elevations, and formed the solid part of the
earth, change the mathematical into a physical form,
of surface.    On the first form; science has made all its
graduated measurements of the earth.    By eleven such
measurements, of which nine were made in this cen-
tury, while the two others date from the old Peruvian
times, and the East Indian astronomy, it has ascer-
tained the incurvations of this surface and the size of
the  earth,   and   it   has   been found   by  this means
that the flattening of the earth spheroid, in which the
denseness of the mass must increase towards the centre.,
- is nearly equal to the ^^th part.    These measure-
ments for ascertaining the incurvations of the earth^s
surface have not only been made by graduated measure-
ments, and by observations of the pendulum oscilla-
tions and the divergence in the  moon's course, by
geometrical astronomic means, "but also from conclu-
sions   on   the   observed   movements,   on the  powers
generated, and by these powers back on their origin.
By these measurements, of which eight were made
in Europe, it has been ascertained that the   semi-
diameter from the centre of the earth to the poles is
3.1. geographical miles shorter than the semi-diameter
from the centre to the equator ; this shows that the
surface of the earth from the poles to the equator is
swelled by a little more than 4*4- times the height of
Mont Blanc.    The observations made by the oscilla-
tions of the pendulum have become of extreme im-
portance  for  science,   and  Humboldt   justly   says:
" When Galileo, as a boy, saw during church service
that by the duration of the oscillations of the cande-
labra the entire height of a church dome might be
measured, he could not suppose that the pendulum,
rod would one day be  carried'from pole to pole to
determine the form of the earth, or rather t<> produce
the conviction that the unequal density of the earth
strata affects the second pendulum by intricate local
influences which reveal themselves similarly on large